In a world where we're used to movie trailers that begin with "In a world where ... " and then continue to reveal the entire plot, you may watch the trailer for Pride and Glory and wonder: Colin Farrell is the dirty cop? Why'd they tell us that? Haven't they just ruined it?

Nope. Not at all. Because Pride and Glory isn't a whodunit, it's a why'd-they-do-it and a how-are-they-gonna-fix-it (or maybe a can-it-be-fixed-at-all). This is not, say, Righteous Kill, which is all about making us wonder and tediously, at that whether De Niro or Pacino is the cop gone wrong.

We learn in the opening minutes of Pride that Farrell's Jimmy Egan is a thoroughly corrupt uniformed member of the New York Police Department, and it's hardly a matter of suspense when we discover the psychopathic depths of his hypocrisy and selfishness. (It is a wonderful cinematic pleasure, though, to see the breathtaking scope of Farrell's talent for creating fiercely emotional characters.)

And we know from the beginning that Edward Norton's Ray Tierney Egan's brother-in-law is torn up over an unspoken-of situation in which he was forced to abandon his principles as a cop and a human being. He's left the NYPD's major case division fast track and now toils in missing persons to avoid ending up in a similar situation.

And then four officers are killed in a bizarre shootout all boys from the squad run by Ray's brother, Francis Tierney Jr. (Noah Emmerich), where Egan is also stationed. What's more, one of the dead officers was Ray's former partner and best friend. Chief of Detectives Francis Tierney Sr. (Jon Voight) convinces Ray to come back to lead the investigation and, you know, protect the interests of all involved. Which seems the perfect setup for just the kind of situation Ray was looking to avoid: having to decide which of his bonds of loyalty is strongest. Is it the one to his fellow cops, the one to his family, or the one to the truth?

Director Gavin O'Connor is the son of an NYPD officer, and he wrote the script with his brother, Gregory, retired cop Robert Hopes and filmmaker Joe Carnahan. Together they've captured a down-to-earth honesty, not just in how the film treats the world of its setting, but in how it treats its audience. It expects that you'll be able to keep up with a fast-moving plot, that you don't need everything spelled out for you, that you won't panic at a little uncaptioned Spanish, and that you don't need to be manipulated to feel something.

There's nothing sentimental here that pretends there's one right answer to Ray's dilemma, or that you can't figure that out for yourself. Good people of all stripes get pushed into corners when allegiances fail to coincide. That's the psychological reality of Pride and Glory. It isn't just a cop movie: It's a people movie set against the immediacy and passion of the cop world.

And no doubt, there's something contemporary about seeing two of the finest Gen-X actors square off against each other on screen: Norton is a coolly intelligent foil to Farrell's explosiveness. But there's something wonderfully old-fashioned, too, about Pride and Glory's sincerity and candidness and muscular integrity. It harkens back to a time when movie-making wasn't seen as a game but as a calling, and maybe it bodes well for more of the same in the future.